#define  _CRT_SECURE_NO_WARNINGS
#include <vector>
using namespace std;

class Solution {
public:
    int uniquePaths(int m, int n) {
        vector<vector<int>> vv(m + 1, vector<int>(n + 1, 0));
        vv[0][1] = 1;
        for (int i = 1; i <= m; i++)
            for (int j = 1; j <= n; j++)
                vv[i][j] = vv[i - 1][j] + vv[i][j - 1];
        return vv[m][n];
    }
};